All Questions
9
questions
-3
votes
1
answer
41
views
Potential energy change is not negative? [closed]
$\Delta U = -(W_{earth} + W_{ball})$
$W_{ball}$ is almost 0, as earth's displacement by the falling ball is super small, so $\Delta y$ of the earth could be negligible and $W_{ball} = 0$. so:
$\Delta ...
- 137
0
votes
1
answer
44
views
How to obtain the equations of motion and trajectory of a particle from the effective potential?
In a certain problem regarding motion of a particle in a gravitational field with axial symmetry, I have an expression of an effective potential $\Phi_{eff}(r,\theta)$. Now, I am interested to study ...
- 2,015
1
vote
2
answers
158
views
Why does the Lagrangian not show particle-interaction? Why are normal/tension forces not considered?
(1) For formulating a lagrangian for a system of particles compared to one free particle, we start with the kinetic energy and formulate a potential energy term that is in terms of each of the radius ...
- 17
-1
votes
3
answers
178
views
Why gravitational potential away from a planet increases?
textbooks----
"potential increases towards infinity and is maximum at infinity"
But that is true only when we are seeing potential w.r.t Earth
EXPLANATION---------
So , as we know that ...
- 444
0
votes
2
answers
57
views
If the change in potential enegry is equal to the negative of the work done, then this principle isn't consistent here in the case freely falling body
Let us assume that a body of mass $m$ falls from height $h_1$ to $h_2$ :
Here the Work done by gravitational force (Conservative force) is :
$$\mathrm{Force \ ×\ Displacement} = mg \ (h_2-h_1) \tag1$$
...
0
votes
2
answers
3k
views
What happens when the PE equals to zero in the potential energy vs intermolecular distance graph? [closed]
In the potential energy versus inter molecular distance graph, we know that atoms/molecules/particles want to be at optimum distance from each other ie $r_0$ and to the left of this position in the ...
1
vote
1
answer
1k
views
When is the effective potential equal to the total energy?
I have a question about the energy of a particle in orbit due to a gravitational attraction. The effective potential given by the gravitational force is defined to be
$$
U_{\text{eff}} = \frac{L^2}{...
- 207
10
votes
4
answers
953
views
The converse of Newton's shell theorem
The shell theorem states that a spherically symmetric body $S$ of mass $m$ has a gravitational field identical to that of a point particle $P$ of mass $m$ located at the center of $S$.
We can ask the ...
- 4,576
-1
votes
1
answer
109
views
Motion of the pendulum and a thought exeriment
When the string (of length $l$) connecting the bob (of mass $m$) of a pendulum makes an angle $\theta$ w.r.t the vertical, its total energy is given by $$E=\frac{1}{2}ml^2\dot{\theta}^2+mgl(1-\cos\...
- 26.8k